Oct 23, 2018 - 02:22 AM
Hello. With those dimensions, the X-Small may be the better fit for you because you don't want it too big because you may have trouble keeping the warmer from sliding down as you ride. But we can always exchange them if they don't fit or some people will also order two sizes to compare and then return the one that doesn't fit for a refund. That would be fine too.
Just let us know if you have any questions at all.